Иш кетма-кетлиги

 
The theoretical part is the order of work 
Optical properties of paper include: whiteness, color, tone, gloss, 
transparency. The degree of whiteness can be evaluated on the Spectrodensitometer 
ET-120HD. 

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During work, optical indicators are measured in a Spectrodensitometer ET-120HD 
spectrocolorimeter. 
The level of whiteness is evaluated in comparison with the "ideal white surface" 
contained in the accessory. According to the standard, the whiteness of the paper is 
paper sample mounted on a black base. 
Refractive coefficients can also be determined using the Spectrodensitometer ET-
120HD. 
 
Work order 
1. The coefficient of return is determined by placing a paper sample on a white base: 
the arithmetic mean value is calculated from five parallel measurements. 
2. To calculate the transparency, the given paper sample is measured by placing it on a 
black base, and the average arithmetic value is calculated from five parallel results, and 
the transparency is calculated using the following formula. 
%
100
0


к
к
Н


Here: 

w 
white is the coefficient of return of a paper sample measured on a white basis: 

b 
are coefficients of return of the paper sample measured on the black base 
 
Job report 
1. Effect of whiteness level on product quality. 
2. Comparing the results obtained for different papers, conclusions are made 
about the level of whiteness and transparency. 
 
Control questions: 
1. What indicators can be used to evaluate optical properties? 
2. How is the whiteness of the paper evaluated? 
3. How is the degree of paper transparency evaluated? 
4. What devices are used to evaluate the whiteness of paper.